Preheat oven to 475F.
Slice your red peppers in half, ensuring all seeds are removed. Place each half, cut-side down onto a parchment lined baking pan.
Cook the red peppers in the oven for 40 minutes, the tops should have black spots on them when you take them out.
Carefully place the red peppers into a container that seals or ziplock bag. Let them sweat for 30 minutes.
Peel the skin off the peppers and discard the skin.
Add the red peppers, sundried tomato, pecorino, garlic, cashews, and white wine vinegar in a food processor or blender. You can also use a stick/handheld blender. Pulse until it resembles a pesto.
Taste and season with salt if needed. Add in your oil and stir with a spoon until it's combined.
Serve with cheese, crackers, or just have it on your sandwiches!